This invention relates to compositions which protect keratinous material, such as skin or hair, from the deleterious effects of detergents and from adverse climatic conditions.
The compositions of the invention accordingly help to maintain the keratinous material in good condition. The invention also relates to a method of treating keratin.
The deleterious effects of compositions containing surfactants upon keratin are well known. These effects are caused, it is thought, by penetration of the surfactant into the keratin surface leading to "leaching out" of oils and moisturizing components essential for good condition of the keratin. This surfactant penetration and "leaching out" of essential oils also affects the ability of the keratin, particularly in the case of skin, to retain water within the tissue and this again leads to poor condition of the keratinous material.
Many attempts have been made in the past to provide compositions for maintaining or improving the condition of skin and hair. The application of protein to skin and hair as cosmetic treatments probably antedates recorded history. Casein, in the form of milk, has been used as a time honored beautifier and more recently has been recommended for use in toilet soaps. U.S. Pat. No. 3,548,056 issued Dec. 15, 1970, described the inclusion of partially degraded proteins having a gel strength of zero Bloom grams in detergent compositions and lotions for application to skin such as dishwashing liquids, etc. Copending commonly assigned U.S. Ser. No. 394,589 filed Sept. 5, 1973, now U.S. Pat. No. 3,898,186, discloses liquid detergent compositions containing nonionic surfactants and unmodified gelatins having a molecular weight of at least 12,500, an iso-electric point between about pH 4.5 and about pH 9.2 and a gel strength between 25 and 300 Bloom grams.
OLS No. 2,151,739 and OLS No. 2,151,740 describe certain fatty derivatives of low molecular weight aminolysates suitable for use in shampoos. B.P. No. 1,122,076 describes the preparation of low molecular weight alcohol soluble protein esters suitable for use in hair spray formulations. Various low molecular weight polypeptides or modified polypeptides are commercially available and recommended for use in cosmetic and shampoo formulations, for instance Hydro Pro 220, Hydro Pro 330, Maypon 4C marketed by the Stepan Chemical Company; Wilson X250, Wilson X1000 and Wilson Aqua Pro marketed by the Wilson Chemical Company. However, none of these materials has proven to be as effective in protecting keratin from the action of detergents as compositions of the present invention, and this is particularly true when the proteins are incorporated in the detergent composition itself. It has been suggested that the emolliency of detergent compositions can be improved by addition of fatty or oily materials but, when used in dishwashing liquids, this usually leads to loss of foaming power or to aesthetic changes which are generally considered undesirable by consumers.
It is an object of the present invention to provide protein-containing compositions which are particularly effective in protecting keratinous material, such as skin or hair, from the deleterious effects of detergents and from adverse climatic conditions, which are effective even when applied to keratin in foaming detergent solutions and which result in no appreciable loss of foaming or cleaning power for detergent solutions containing them.